When it’s really hot outside, everyone and everything seems to tire out faster, including your car battery. In this post, we’ll go over how heat affects your car battery, what you can do to protect your battery, and some recommendations for batteries built to resist heat.
How Heat Affects Your Car Battery
Hot weather can affect your car battery in multiple ways. For example, heat can cause the liquids in a conventional battery to evaporate. Battery fluid creates the electricity needed to power the battery. If there’s not enough fluid, the battery won’t start. Heat also accelerates corrosion on the battery, putting it at further risk of failure.
In extreme temperatures, a chemical reaction known as thermal runaway can occur inside your battery. This causes the battery temperature to rapidly increase and can sometimes cause a fire.
These effects decrease the battery’s charge and ultimately shorten its lifespan.
Symptoms of Heat-Related Battery Failure
When driving in the heat, you may notice certain indications that your car battery is starting to fail. Here are some examples:
- The car is having trouble starting.
- The car lights (internal or external) are flickering or dimmed.
- The check engine light or battery warning light is on.
- The car battery case appears swollen.
- There is visible corrosion on the battery pack.
If you notice any of these symptoms, assess your battery right away. Sometimes, you may just need to jumpstart or charge your battery. In other cases (e.g., if there’s severe corrosion or swelling), you’ll need a new battery. If you’re unsure how serious the damage is, have it assessed by a professional.
Preventing Battery Failure
To protect your battery during those hot summer months, implement a maintenance routine to keep it in top condition.
Charge It Up
The optimal charge level for most car batteries is between 50% and 80%. If you drive frequently (four or five times a week), charge your battery every four to six weeks to keep it in this range. If you won’t be driving for several weeks or longer, top your battery up every week or two so it’ll be ready when you need it. When possible, use a trickle charger for slow and steady charging.
If your car battery is completely dead, follow to recharge it.
Check for Damage
Assess your battery for signs of damage, such as bloating or corrosion, at least twice a year. If your battery requires water, check the water level and top it up as needed. For AGM batteries, top up the battery fluid.
Electric vehicle (EV) batteries do not require the same maintenance as gas-powered car batteries, but you can still protect them from heat damage with these tips:
- Avoid frequent fast-charging.
- Put insulation foam around the battery pack.
- Park in the shade.
- Keep the battery charged between 20% and 80% capacity.
Best Batteries for Resisting Heat
The best batteries for resisting heat are those with AGM (Absorbent Glass Mat) technology. NAPA has a line of AGM batteries for all different vehicles, including passenger cars.
The NAPA The Legend Premium AGM Battery offers enhanced durability for better performance and longer service life than the average battery. It’s also able to start in challenging conditions that other batteries may crumble under, such as infrequent vehicle use, stop-and-start traffic, and hefty power drains from electronics.
Use the “Add New Vehicle” feature on the top left corner of the NAPA website for a guaranteed fit on all automotive products, including the right battery size.
For more advice on battery maintenance, refer to your owner’s manual or visit your local NAPA AUTOPRO Service Centre to speak to a mechanic.